1. Field of the Invention
The present invention relates to sun trackers.
2. Description of the Related Art
The tracker working according to the gravitational force principle is known (see DE-3421411 Cl). It serves for tracking the sun movement with the sun collectors, thus increasing a solar facility's efficiency.
In this system, the solar collectors are carried by a rotary pole, supported by a chamber of variable volume. The fluid contained in the chamber is displaced from the chamber by the dead load force of the sun collectors and of the rotary pole, penetrating through a nozzle in this process. The rotary pole thus sinks and is rotated about its vertical axis through the interaction of a bolt with a helical groove guide, tracking the sun movement from east to west. The return to the initial position "to the east" is performed every morning at sunrise by lifting the rotary pole with muscle power; tracking along the horizontal axis, according to the elevation angle is not performed in case of such tracker system.
In spite of the robust construction, this tracker has proved to be not without problems as far as the technical application is concerned.
For one, this tracker does not work without the daily intervention of an operator, lifting the rotary pole and thus positioning the sun collectors in their initial position.
Secondly, the sun collectors' weight is limited because of the required human muscle power.
Thirdly, the varying ambient temperature causes, based on the temperature dependent viscosity of the fluid in the chamber, deficiencies as regards the tracking speed which can lead to considerable failures in case of larger temperature differences, for example in summer/winter cycles and can thus under certain circumstances make the system useless.
For the above reasons, this construction proves hardly suitable and/or unsuitable for application in such solar assemblies as solar-thermal collectors, storage collectors, sunlight concentrators, flat mirrors for solar towers but also in photovoltaic modules with amplification mirrors.